Powder formulations

ABSTRACT

This invention relates to new powder formulations consisting of (a) at least one agrochemical active compound, (b) at least one biodegradable hydroxyl-containing polyester, optionally in a mixture with one or more further biodegradable polymers, and (c) optionally, additives, and which have a particle diameter of under 125 μm, and further relates to a process for the preparation of the new powder formulations and to their use for applying agrochemical active compounds to plants and/or their environment.

The present invention relates to new powder formulations comprisingagrochemical active compounds and polymers, to a process for thepreparation of these formulations, and to their use for applyingagrochemical active compounds.

Microparticles containing specific polymers as a mixture withagrochemical active compounds are also known from WO 99-00 013. Thesepreparations are made by dissolving polymers and agrochemical activecompounds in an organic solvent which is sparingly miscible with water,then dispersing this solution in water using emulsifiers, thereuponevaporating the solvent, and separating the resulting microparticlesfrom the aqueous phase by decanting and/or filtration and subsequentlydrying them. However, the disadvantage of this process is that a largenumber of complicated procedures have to be carried out and thus the useof relatively large apparatuses is necessary when carrying out theprocess on an industrial scale. The fact that the organic solventsrequired for dissolving the components must subsequently be removed isadditionally disadvantageous.

Furthermore, U.S. Pat. No. 5,725,869 also describes methods for thepreparation of polymer microparticles in which agrochemical activecompounds are present. Again, these methods are very complicated andtherefore hardly suitable for use on an industrial scale.

There have now been found new powder formulations consisting of

-   -   at least one agrochemical active compound,    -   at least one biodegradable hydroxyl-containing polyester, if        appropriate in a mixture with one or more further biodegradable        polymers, and,    -   if appropriate, additives        and which have a particle diameter of under 125 μm.

It has furthermore been found that the powder formulations according tothe invention can be prepared by homogenizing a mixture of

-   -   at least one agrochemical active compound,    -   at least one biodegradable hydroxyl-containing polyester, if        appropriate in a mixture with one or more further biodegradable        polymers, and,    -   if appropriate, additives        at temperatures of between 50° C. and 180° C. in the melt and        comminuting the mixture after cooling in such a way as to obtain        a powder in which the particles have a diameter under 125 μm.

Finally, it has been found that the powder formulations according to theinvention are highly suitable for applying the agrochemical activecompounds which they contain to plants and/or their environment.

It must be considered as extremely surprising that the powderformulations according to the invention are more suitable for applyingthe agrochemical active compounds which they contain than the prior-artpreparations of the most similar constitution. What is particularlyunexpected is that the active components are released in thespecifically desired amount over a prolonged period.

Furthermore, it had to be assumed that carrying out the processaccording to the invention would, after cooling of the melt, result insoft resins which are sticky at room temperature since mixtures ofpolyesters and agrochemical active compounds generally have low meltingpoints. However, in contrast to what was expected, products are obtainedwhich are so brittle that they can be comminuted with the aid ofcustomary mills without additional cooling to give free-flowing powderswhich do not form aggregates.

The powder formulations according to the invention contain one or moreagrochemical active compounds.

Agrochemical active compounds are understood as meaning; for the presentpurpose, all substances which are customary for the treatment of plants.Substances which may preferably be mentioned are fungicides,bactericides, insecticides, acaricides, nematicides, herbicides, plantgrowth regulators, plant nutrients and repellents. Solid agrochemicalactive compounds are preferred.

Examples of fungicides which may be mentioned are:

-   2-anilino-4-methyl-6-cyclopropylpyrimidine;    2′,6′-dibromo-2-methyl-4′-trifluoro-methoxy-4′-trifluoromethyl-1,3-thiazole-5-carboxanilide;    2,6-dichloro-N-(4-trifluoro-methylbenzyl)benzamide;    (E)-2-methoximino-N-methyl-2-(2-phenoxyphenyl)acetamide;    8-hydroxyquinoline sulphate; methyl    (E)-2-{2-[6-(2-cyanophenoxy)-pyrimidin-4-yloxy]phenyl}-3-methoxyacrylate;    methyl (E)-rnethoximino[alpha-(o-tolyloxy)-o-tolyl]acetate;    2-phenylphenol (OPP), aldimorph, ampropylfos, anilazin, azaconazol,-   benalaxyl, benodanil, benomyl, binapacryl, biphenyl, bitertanol,    blasticidin-S, bromuconazole, bupirimate, buthiobate,-   calcium polysulphide, captafol, captan, carbendazim, carboxin,    quinomethionate, chloroneb, chloropicrin, chlorothalonil,    chlozolinate, cufraneb, cymoxanil, cyproconazole, cyprofuram,    carpropamid,-   dichlorophen, diclobutrazol, dichlofluanid, diclomezine, dicloran,    diethofencarb, difenoconazole, dimethirimol, dimethomorph,    diniconazole, dinocap, diphenylamine, dipyrithion, ditalimfos,    dithianon, dodine, drazoxolon, edifenphos, epoxyconazole, ethirimol,    etridiazole,-   fenarimol, fenbuconazole, fenfuram, fenitropan, fenpiclonil,    fenpropidin, fenpropimorph, fentin acetate, fentin hydroxide,    ferbam, ferimzone, fluazinam, fludioxonil, fluoromide,    fluquinconazole, flusilazole, flusulfamide, flutolanil, flutriafol,    folpet, fosetyl-aluminium, fthalide, fuberidazol, furalaxyl,    furmecyclox, fenhexamid,-   guazatine,-   hexachlorobenzene, hexaconazole, hymexazol,-   imazalil, imibenconazole, iinoctadine, iprobenfos (IBP), iprodione,    isoprothiolan, iprovalicarb,-   kasugamycin, copper, preparations such as: copper hydroxide, copper    naphthenate, copper oxychloride, copper sulphate, copper oxide,    oxine-copper and Bordeaux mixture,-   mancopper, mancozeb, maneb, mepanipyrim, mepronil, metalaxyl,    metconazole, methasulfocarb, methfuroxam, metiram, metsulfovax,    myclobutanil,-   nickel dimethyldithiocarbamate, nitrothal-isopropyl, nuarimol,-   ofurace, oxadixyl, oxamocarb, oxycarboxin,-   pefurazoate, penconazole, pencycuron, phosdiphenr, pimaricin,    piperalin, polyoxin, probenazole, prochloraz, procymidon,    propamocarb, propiconazole, propineb, pyra-zophos, pyrifenox,    pyrimethanil, pyroquilon,-   quintozene (PCNB), quinoxyfen,-   sulfur and sulfur preparations, spiroxamine,-   tebuconazole, tecloftalam, tecnazene, tetraconazole, thiabendazole,    thicyofen, thio-phanate-methyl, thiram, tolclophos-methyl,    tolylfluanid, triadimefon, triadimenol, triazoxide, trichlamide,    tricyclazole, tridemorph, triflumizole, triforine, triticonazole,    trifloxystrobin,-   validamycin a, vinclozolin,-   zineb, ziram, and-   2-[2-(1-chlorocyclopropyl)-3-(2-chlorophenyl)-2-hydroxypropyl]-2,4-dihydro-[1,2,4]-triazole-3-thione.

Examples of bactericides which may be mentioned are:

-   -   bronopol, dichlorophen, nitrapyrin, nickel        dimethyldithiocarbamate, kasugamycin, octhilinone,        furancarboxylic acid, oxytetracyclin, probenazole, streptomycin,        tecloftalam, copper sulphate and other copper preparations.

Examples of insecticides, acaridices and nematicides which may bementioned are:

-   abamectin, acephate, acrinathrin, alanycarb, aldicarb, alphamethrin,    amitraz, avermectin, AZ 60541, azadirachtin, azinphos A, azinphos M,    azocyclotin,-   Bacillus thuringiensis,    4-bromo-2-(4-chlorophenyl)-1-(ethoxymethyl)-5-(trifluoromethyl)-1H-pyrrole-3-carbonitrile,    bendiocarb, benfuracarb, bensultap, betacyfluthrin, bifenthrin,    BPMC, brofenprox, bromophos A, bufencarb, buprofezin, butocarboxin,    butylpyridaben,-   cadusafos, carbaryl, carbofuran, carbophenothion, carbosulfan,    cartap, chloethocarb, chloretoxyfos, chlorfenvinphos,    chlorfluazuron, chlormephos,    N-[(6-chloro-3-pyridinyl)-methyl]-N′-cyano-N-methyl-ethaniridamide,    chlorpyrifos, chlorpyrifos M, cis-resmethrin, clocythrin,    clofentezine, cyanophos, cycloprothrin, cyfluthrin, cyhalothrin,    cyhexatin, cypermethrin, cyromazine,-   deltamethrin, demeton-M, demeton-S, demeton-S-methyl, diafenthiuron,    diazinon, dichlofenthion, dichlorvos, dicliphos, dicrotophos,    diethion, diflubenzuron, dimethoate,-   dimethylvinphos, dioxathion, disulfoton,-   emamectin, esfenvalerate, ethiofencarb, ethion, ethofenprox,    ethoprophos, etrimphos, fenamiphosi, fenazaquin, fenbutatin oxide,    fenitrothion, fenobuicarb, fenothiocarb, fenoxycarb, fenpropathrin,    fenpyrad, fenpyroximate, fenthion, fenvalerate, fipronil, fluazuron,    flucycloxuron, flucythrinate, flufenoxuroni, flufenprox,    fluvalinate, fono-phos, formothion, fosthiazate, fubfenprox,    furathiocarbi,-   HCH, heptenophos, hexaflumuron, hexythiazox,-   imidacloprid, iprobenfos, isazophos, isofenphos, isoprocarb,    isoxathion, ivermectin, lambda-cyhalothrin, lufenuron,-   malathion, mecarbam, mevinphos, mesulfenphos, metaldehyde,    methacrifosi, metha-midophos, methidathion, methiocarb, methomyl,    metolcarb, milbemectin, mono-crotophos, moxidectin,-   naled, NC 184, nitenpyram,-   omethoate, oxamyl, oxydemethon M, oxydeprofos,-   parathion A, parathion M, permethrin, phenthoate, phorate,    phosalone, phosmet, phosphamidon, phoxim, pirimicarb, pirirniphos M,    pirimiphos A, profenophos, promecarb, propaphos, propoxur,    prothiophos, prothoate, pymetrozin, pyrachlophos, pyridaphenthion,    pyresmethrin, pyrethrum, pyridaben, pyrimidifen, pyriproxifen,-   quinalphos,-   salithion, sebufos, silafluofen, sulfotep, sulprofos,-   tebufenozide, tebufenpyrad, tebupirirniphos, teflubenzuron,    tefluthrin, temephos, terbam, terbufos; tetrachlorvinphob    viicloprid, rthiafenox, thiamethoxam, thiodicarb, thiofanox,    thiomethon, thionazin, thuringiensin, tralomethrin, transfluthrin,    triarathen, triazophos, triazuron, trichlorfon, triflumuron,    trimethacarb,-   vamidothion, XMC, xylylcarb, zetamethrin.

Examples of herbicides which may be mentioned are:

-   -   anilides such as, for example, diflufenican and propanil;        arylcarboxylic acids, such as, for example, dichloropicolinic        acid, dicamba and picloram; aryloxyalkanoic acids such as, for        example, 2,4-D, 2,4-DB, 2,4-DP, fluroxypyr, MCPA, MCPP and        triclopyr; aryloxyphenoxyalkanoic esters such as, for example,        diclofop-methyl, fenoxaprop-ethyl, fluazifop-butyl,        haloxyfop-methyl and quizalofop-ethyl; azinones such as, for        example, chloridazon and norflurazon; carbamates such as, for        example, chlorpropham, desmedipham, phenmedipham and propham;        chloroacetanilides such as, for example, alachlor, acetochlor,        butachlor, metazachlor, metolachlor, pretilachlor and        propachlor; dinitroanilines such as, for example, oryzalin,        pendimethalin and trifluralin; diphenyl ethers such as, for        example, acifluorfen, bifenox, fluoroglycofen, fomesafen,        halosafen, lactofen and oxyfluorofen; ureas such as, for        example, chlortoluron, diuron, fluometuron, isoproturon, linuron        and metha-benzthiazuron; hydroxylamines such as, for example,        alloxydim, clethodim, cycloxydim, sethoxydim and tralkoxydim;        imidazolinones such as, for example, imazethapyr,        imazamethabenz, imazapyr and imazaquin; nitriles such as, for        example, bromoxynil, dichlobenil and ioxynil; oxyacetamides such        as, for example, mefenacet; sulphonylureas such as, for example,        amidosulfuron, bensulfuron-methyl, chlorimuron-ethyl,        chlorsulfuron, cinosulfuron, metsulfuron-methyl, nicosulfuron,        primisulfuron, pyrazosulfuron-ethyl, thifensulfuron-methyl,        triasulfuron and tribenuron-methyl; thiocarbamates such as, for        example, butylate, cycloate, di-allate, EPTC, esprocarb,        molinate, prosulfocarb, thiobencarb and tri-allate; triazines        such as, for example, atrazine, cyanazine, simazine, simetryne,        terbutryne and terbutylazine; triazinones such as, for example,        hexazinon, metamitron and metribuzin; others such as, for        example, aminotriazole, benfuresate, bentazone, cinmethylin,        clomazone, clopyralid, difenzoquat, dithiopyr, ethofumesate,        fluorochloridone, glufosinate, glyphosate, isoxaben, pyridate,        quinchlorac, quinmerac, sulphosate and tridiphane. Others which        may be mentioned are        4-amino-N-(1,1-dimethylethyl)-4,5-dihydro-3-(1-metylethyl)-5-oxo-1H-1,2,4-triazole-1-carb-oxamide        and methyl        2-((((4,5-dihdydro-4-methyl-5-oxo-3-propoxy-1H-1,2,4-triazol-1-yl)carbonyl)amino)sulphonyl)benzoate.

Examples of plant growth regulators which may be mentioned arechlorcholin chloride and ethephon.

Examples of plant nutrients which may be mentioned are customaryinorganic or organic fertilizers for providing plants with macro- and/ormicronutrients.

Examples of repellents which may be mentioned are diethyltoluamide,ethylhexanediol and butopyronoxyl.

Examples which may be mentioned of insecticides which may preferably bepresent in the powder formulations according to the invention are thefollowing active compounds:

-   -   imidacloprid, thiacloprid, thiamethoxam, acetamiprid,        clothianidin, betacyfluthrin, cypermethrin, transfluthrin,        lambda-cyhalothrin and azinphos-methyl.

Examples which may be mentioned of herbicides which can preferably bepresent in the powder formulations according to the invention are thefollowing active compounds:

-   -   propoxycarbazone-sodium, flucarbazone-sodium, amicarbazone,        dichlobenil and phenyluracils of the formula

in which the substituents R¹, R² and R³ have the meanings statedhereinbelow. R¹ R² R³

—CN —CH₃

—CN —CH₃

—CN —CH₃

—CH₃

—CN —CH₃

—CN —CH₃

—CN —CH₃

—CN —CH₃

—CN —CH₃

—CN —CH₃

—CN —CH₃

—CN —CH₃

—CN —CH₃

—CN —CH₃

—CN —CH₃

—CN —NH₂

—CN —NH₂

The powder formulations according to the invention contain one or morebiodegradable hydroxyl-containing polyesters, if-appropriate in amixture with one or more further biodegradable polymers.

Polyesters which are preferably suitable are those-esters which arederived from aliphatic, cycloaliphatic, aromatic and/or heterocyclicsaturated or unsaturated carboxylic acids which can be substituted byhalogen atoms. Examples which may be mentioned are:

-   -   succinic acid, adipic acid, suberic acid, azelaic acid, sebacic        acid, phthalic acid, terephthalic acid, isophthalic acid,        trimellithic acid, pyromellithic acid, tetra-hydrophthalic acid,        hexahydrophthalic acid, endomethylenetetrahydrophthalic acid,        glutaric acid, maleic acid, fumaric acid and—if obtainable—their        anhydrides,    -   furthermore dimeric and trimeric fatty acids such as oleic acid,        if appropriate in a mixture with monomeric fatty acids,    -   moreover dimethyl terephthalate, bisglycol terephthalate,    -   furthermore cyclic monocarboxylic acids such as benzoic acid,        p-tert-butylbenzoic acid or hexahydrobenzoic acid.

Suitable alcohol components from which the polyesters are derived are,preferably, polyhydric alcohols such as ethylene glycol, 1,2-propyleneglycol, 1,3-propylene glycol, 1,4-butylene glycol, 2,3-butylene glycol,di-β-hydroxyethyl-butanediol, 1,6-hexanediol, 1,8-octanediol, neopentylglycol, cyclohexanediol, 1,4-bis-(hydroxymethyl)cyclohexane,2,2-bis(4-hydroxycyclohexyl)propane,2,2-bis(4-(β-hydroxyethoxy)phenyl)propane, 2-methyl-1,3-propanediol,glycerol, trimethylolpropane, 1,2,6-hexanetriol, 1,4-butanediol,tris(β-hydroxyethyl)-isocyanurate, trimethylolethane, pentaerythritol,quinitol, mannitol and sorbitol, formitol and their hydroxyalkylationproducts, methyl glycol, diethylene glycol, triethylene glycol,tetraethylene glycol, dipropylene glycol, tripropylene glycol,dibutylene glycol, polybutylene glycols and xylylene glycol.

Others which may also be present in minor quantities are mono- orpolyesters of lactones, such as ε-caprolactone, or of hydroxycarboxylicacids, such as hydroxypivalic acid, hydroxydecanoic acid orhydroxycaproic acid, furthermore polyesters of the abovementionedpolycarboxylic acids and/or their derivatives and polyphenols such ashydroquinone, bisphenol-A, 4,4′-dihydroxybiphenyl orbis(4-hydroxyphenyl) sulphone; polyesters modified with fatty acid (oilalkyds) and naturally occurring saturated or unsaturated polyesters,their degradation products or transesterification products with polyolssuch as castor oil, tall oil, soya oil, linseed oil; carbonic acidpolyesters which are obtainable from hydroquinone, diphenylolpropane,p-xylylene glycol, ethylene glycol, butanediol or 1,6-hexanediol andother polyols by customary condensation reactions, for example withphosgene or diethyl carbonate or diphenyl carbonate, or from cycliccarbonates such as glycol carbonate or vinylidene carbonate; silic acidpolyesters, polysiloxanes such as, for example, the products which canbe obtained by hydrolyzing dialkyldichlorosilanes with water andsubsequently treating the product with polyalcohols or which can beobtained by an addition reaction of polysiloxane dihydrides and olefinssuch as allyl alcohol or acrylic acid.

Other suitable polyesters are reaction products of mono-, di- orpolycarboxylic acids and glycidyl compounds as are described, forexample, in DIE-A 24 10 513.

Examples of glycidyl compounds are esters of 2,3-epoxy-1-propanol withmonobasic acids having 4 to 18 carbon atoms, such as glycidyl palmitate,glycidyl laurate and glycidyl stearate; alkylene oxides having 4 to 18carbon atoms such as butylene oxide and glycidyl ethers, such as octylglycidyl ether.

Examples of di- and polycarboxylic acids are the substances mentioned inthe list hereinbelow under item 2.

Examples of monocarboxylic acids are the substances mentioned in thelist hereinbelow under item 3.

Other preferred polyesters in the case of the powder formulationsaccording to the invention are monomeric esters such asbis(hydroxyalkyl) carboxylate, furthermore monocarboxylic esters of morethan dihydric polyols, and also oligoesters which can be prepared bysubjecting alcohols and carboxylic acids to condensation reactions, asthey are mentioned in the list hereinbelow.

List of suitable starting materials.

-   -   1. Alcohols having 2 to 24, preferably 2 to 10, carbon atoms,        and 2 to 60H groups bonded to nonaromatic carbon atoms, for        example ethylene glycol, propylene glycols, diethylene glycol,        dipropylene glycol, butanediols, neopentyl glycol, hexanediols,        hexanetriols, perhydrobisphenol, dimethylolcyclohexane,        glycerol, trimethylolethane, trimethylolpropane,        pentaerythritol, dipentaerythritol, mannitol;    -   2. di- and polycarboxylic acids having 4 to 36 carbon atoms and        2 to 4 carboxyl groups, and their esterifiable derivatives such        as anhydrides and esters, for example phthalic acid(anhydride),        isophthalic acid, terephthalic acid, alkyltetrahydrophthalic        acid, endomethylenetetrahydrophthalic anhydride, adipic acid,        succinic acid, maleic acid, fumaric acid, dimeric fatty acids,        trimellithic acid, pyromellithic acid, azelaic acid;    -   3. monocarboxylic acids having 6 to 24 carbon atoms, for example        caprylic acid, 2-ethylhexanoic acid, benzoic acid,        p-tert-butylbenzoic acid, hexahydrobenzoic acid, monocarboxylic        acid mixtures of natural oils and fats such as coconut oil fatty        acid, soya oil fatty acid, recinene fatty acid, hydrogenated and        isomerized fatty acids such as “conjuvandol” fatty acid, and        mixtures of these, it also being possible to employ the fatty        acids as glycerides and to react them with transesterification        and/or dehydration;    -   4. monohydric alcohols having 1 to 18 carbon atoms, for example        methanol, ethanol, isopropanol, cyclohexanol, benzyl alcohol,        isodecanol, nonanol, octanol, oleyl alcohol, octadecanol.

Especially preferred are hydroxyl-containing terephthalic acidpolyesters whose average molecular weight is between 1 000 g/mol and 20000 g/mol, preferably between 1 500 g/mol and 15 000 g/mol, based on thenumber average molecular weight.

The hydroxyl-containing polyesters which are present in the powderformulations according to the invention generally have an OHfunctionality of ≧2 to ≦7, preferably 2.1 to 4.5, hydroxyl numbers ofbetween 20 and 120 mg KOH/g, preferably between 30 and 100 mg KOH/g,viscosities of <100 000 mPa.s, preferably <40 000 mPa.s at 160° C. andmelting points of from ≧65° C. to ≦130° C., preferably 75° C. to 100° C.

The polyesters which are present in the powder formulations according tothe invention are known or can be prepared in a simple manner bycustomary methods.

Thus, such polyesters are obtained, for example, by subjecting thestarting materials in question to a condensation reaction under an inertgas atmosphere at temperatures of between 100° C. and 260° C.,preferably between 130° C. and 220° C., in the melt or using solventswith azeotropic removal of water (cf. Houben-Weyl “Methoden derOrganischen Chemie” [Methods in Organic Chemistry], Vol. 14/2, pages 1to 4, 21 to 23 and 44 to 46, Georg Thieme Verlag, Stuttgart 1963, and C.R. Martens “Alkyd Resins”, pages 51 to 59, Reinhold Plastics Appln.Series, Reinhold Publishing Comp., New York 1961).

Suitable additional polymers which may be present in the powderformulations according to the invention are acrylate resins which can beobtained, for example, from the monomers listed hereinbelow by homo- orcopolymerization.

Esters of acrylic acid and methacrylic acid with dihydric, saturated,aliphatic alcohols having 2 to 4 carbon atoms, such as, for example,2-hydroxyethylacrylate, 2-hydroxypropyl acrylate, 4-hydroxybutylacrylate and the corresponding methacrylic esters; acrylic esters andmethacrylic esters having 1 to 18, preferably 1 to 8, carbon atoms inthe alcohol moiety such as, for example, methyl acrylate, ethylacrylate, propyl acrylate, isopropyl acrylate, n-butyl acrylate,tert-butyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, and thecorresponding methacrylic esters, cyclohexyl acrylate and cyclohexylmethacrylate; acrylonitrile and methacrylonitrile; acrylamide andmethacrylamide; N-methoxymethyl(meth)acrylamide.

Preferred acrylate resins are copolymers of

-   -   a) 0 to 50% by weight of monoesters of acrylic acid or        methacrylic acid with two- or polyhydric alcohols, such as        1,4-butanediol monoacrylate, hydroxypropyl (meth)acrylate;        furthermore vinyl glycol, vinylthioethanol, allyl alcohol,        1,4-butanediol monovinyl ether;    -   b) 5 to 95% by weight of esters of acrylic acid or methacrylic        acid with monohydric alcohols containing 1 to 12 carbon atoms,        such as, for example, methyl methacrylate, ethyl acrylate,        n-butyl acrylate or 2-ethylhexyl acrylate;    -   c) 0 to 50% by weight of aromatic vinyl compounds, such as        styrene, methylstyrene or vinyltoluene;    -   d) 0 to 20% by weight of other monomers with functional groups        such as, for example, acrylic acid, methacrylic acid, crotonic        acid, itaconic acid, maleic acid, fumaric acid, maleic        anhydride, maleic monoester, acrylamide, methacrylamide,        acrylonitrile or N-methylol(meth)acrylamide and glycidyl        (meth)acrylate, the content of group a) and/or d) amounting to        at least 5% by weight.

The abovementioned acrylate resins are known or can be prepared in asimple manner by customary methods. Thus, such acrylate resins areobtained, for example, by solvent polymerization, bead polymerization,emulsion polymerization or precipitation polymerization, but preferablyby mass polymerization, which, in turn, can be initiated by UV light orother polymerization initiators. Suitable polymerization initiators areperoxides- or azo compounds such as, for example, dibenzoyl peroxide,tert-butyl perbenzoate or azodiisobutyronitrile. The molecular weightcan be adjusted for example using sulphur compounds such astert-dodecylmercaptan.

Naturally, mixtures of a plurality of substances may be employed aspolyhydroxyl compounds.

Suitable esterification catalysts are inorganic oxides and salts of tin,zinc, manganese, titanium and bismuth. Organotin compounds such as, forexample, tin(II) acetate, tin(II) octoate, tin(II) laurate, dibutyltindiacetate, dibutyltin dilaurate, dibutyltin maleate or dioctyltindiacetate may likewise be used as catalysts. In general, the catalystsare employed in an amount of between 0.01 and 0.5% by weight based onthe total amount of the reactants used.

Polyesters which are present in the powder formulations according to theinvention are especially preferably esters which are derived from theacids and alcohols listed hereinbelow.

Especially preferred alcohols are glycols such as ethylene glycol,1,2-propanediol, 1,4-butanediol and isomers, furthermore neopentylglycol, 1,6-hexanediol and isomers,4,4′-dihydroxydicyclohexyl-2,2-propane, cyclohexanediol,1,4-bis-(hydroxymethyl)cyclohexane, and furthermore polyols such astrimethylolpropane, hexanetriol and pentaerythritol.

Especially preferred acids are di- or polycarboxylic acids such asterephthalic acid, tetrahydrophthalic acid, phthalic acid, isophthalicacid, trimellithic and adipic acid.

Especially preferred are hydroxyl-containing polyesters comprising

-   -   50 to 65% by weight of aromatic polycarboxylic acids,    -   30 to 45% by weight of aliphatic glycols and    -   0 to 5% by weight of aliphatic triols.

Polymers which are optionally additionally present arehydroxyl-containing copolymers as are formed by copolymerization ofhydroxyalkyl acrylates or hydroxyalkyl methacrylates with acrylic estersor methacrylic esters and, if appropriate, further unsaturated monomers.Unsaturated monomers are, in this context, for example substancesobtainable from styrene/maleic acid copolymerization by partialesterification of the acid groups with ethylene oxide (cf. DE-A 21 37239).

The softening points measured, by differential thermoanalysis (=DTA) ofthe preferred hydroxyl-containing polyesters are generally between 40°C. and 140° C., preferably between 45° C. and 100° C. The hydroxylnumbers of these materials are generally between 25 and 200, preferablybetween 30 and 130. The molecular weight of these materials which can becalculated from the functionality and the hydroxyl content is generallybetween 400 and 10 000, preferably between 1 000 and 5 000.

Suitable additives which may be present in the plant treatmentcompositions according to the invention are all of the materials whichcan conventionally be employed in such polymer preparations. Preferablysuitable are fillers, and lubricants, glidants and stabilizers knownfrom polymer technology.

Examples of fillers which may be mentioned are: titanium dioxide, bariumsulphate, furthermore aluminium oxides, silicas, clays, precipitated orcolloidal silicon dioxide, and phosphates.

Examples of lubricants and glidants which may be mentioned are:magnesium stearate, stearic acid, talc and bentonites.

Suitable stabilizers are antioxidants and substances which protect thepolymers from undesired degradation during processing.

The concentrations of the individual components in the powderformulations according to the invention can be varied within asubstantial range. Thus,

-   -   the content of agrochemical active compounds is generally        between 1 and 50% by weight, preferably between 5 and 40% by        weight, the content of hydroxyl-containing polyesters, if        appropriate in a mixture with additional polymers, is generally        between 50 and 99% by weight, preferably between 55 and 95% by        weight, and the additive content is generally between 0 and 30%        by weight, preferably between 0 and 20% by weight.

When carrying out the process according to the invention, a procedure isgenerally followed in which the polymer components are melted attemperatures of between 50° C. and 180° C., preferably between 120° C.and 180° C., especially preferably between 140° C. and 170° C., and oneor more agrochemical active compounds and, if appropriate, additives arethen introduced with stirring. The resulting fluid and homogeneousmixture is transported to cooling belts or cooling drums with the aid ofcustomary discharge devices. When cold, the solidified product isremoved from the cooling device and crushed. The crude granules obtainedare subsequently comminuted with customary grinding apparatuses andscreened to give a powder in which the particles have a diameter ofunder 125 μm.

Suitable grinding apparatuses are all mills which are conventionallyemployed for such purposes. Mills which can preferably be used arepinned-disc mills, ball mills, jet mills or classifier mills, a millwhich may be mentioned by way of example being an ACM 2 type mill fromHosokawa Mikropul.

The powder formulations according to the invention, as such or afteraddition of further formulation auxiliaries, can be employed forapplying agrochemical active compounds in crop protection inagriculture, forestry or horticulture. Formulation auxiliaries which aresuitable in this context are all those components which can generally beused in plant treatment compositions such as, for example, colorants,wetters, dispersants, emulsifiers, antifoams, preservatives, humectantcomponents, antifreeze agents, secondary thickeners, solvents, and, whenseed-dressing products are prepared, also stickers.

Colorants which can be employed for the further processing of thepowders according to the invention as plant treatment compositions areall those colorants which are customary for such purposes. Colorantswhich can be used are sparingly water-soluble pigments and alsowater-soluble dyes. Examples which may be mentioned are those knownunder the names Rhodamin B, C.I.Pigment Red 112 and C.I.Solvent Red 1.

Suitable wetters which can be used for formulating the powders accordingto the invention are all those materials which promote wetting and whichare customary for the formulation of agrochemical active compounds.Materials which can preferably be used are alkylnaphthalenesulphonates,such as diisopropylnaphthalenesulphonate ordiisobutylnaphthalenesulphonate.

Dispersants and/or emulsifiers which are suitable for formulating thepowders according to the invention are all those nonionic, anionic andcationic dispersants which are conventionally used in the formulation ofagrochemical active compounds. Materials which can preferably be usedare nonionic or anionic dispersants or mixtures of nonionic or anionicdispersants. Suitable nonionic dispersants which may be mentioned are,in particular, ethylene oxide/propylene, oxide block polymers,alkylphenol polyglycol ethers and tristyrylphenol polyglycol ethers, andtheir phosphated or sulphated derivatives. Suitable anionic dispersantsare, in particular, lignosulphonates, polyacrylic acid salts andarylsulphonate/formaldehyde condensates.

Antifoams which can be used for formulating the powders according to theinvention are, all those materials which inhibit foaming and which aresuitable for the formulation of agrochemical active compounds. Materialswhich can preferably be used are silicon antifoams and magnesiumstearate.

Preservatives which can's be used for formulating the powders accordingto the invention are all those substances which are conventionally usedfor such purposes for the formulation of agrochemical active compounds.Examples which may be mentioned are dichlorophene and benzyl alcoholhemiformal.

Possible humectant components and antifreeze agents which can be usedfor formulating the powders according to the invention are all thosematerials which can be employed for such purposes in agrochemicalcompositions. Substances which can preferably be used are polyhydricalcohols such as glycerol, ethanediol, propanediol and polyethyleneglycols of various molecular weights.

Suitable secondary thickeners which can be used for formulating thepowders according to the invention are all substances which can beemployed for such purposes in agrochemical compositions. Possiblesubstances are, preferably, cellulose derivatives, acrylic acidderivatives, xanthan, modified clays and highly dispersed silica.

Possible solvents which can be used for formulating the powdersaccording to the invention are all organic solvents which can beemployed in agrocheniucal compositions. Substances which are preferablysuitable are ketones such as methyl isobutyl ketone and cylohexanone,furthermore amides, such as dimethylformamide, moreover cyclic compoundssuch as N-methyl-pyrrolidone, N-octyl-pyrrolidone,N-dodecyl-pyrrolidone, N-octyl-caprolactam, N-dodecyl-caprolactam andγ-butyrolactone, in addition strongly polar solvents such asdimethylsulfoxide, furthermore aromatic hydrocarbons such as xylene, orelse esters such as propylene glycol monomethyl ether acetate, dibutyladipate, hexyl acetate, heptyl acetate, tri-n-butyl citrates, diethylphthalate and di-n-butyl phthalate, and, moreover, alcohols such asethanol, n- and i-propanol, n- and i-butanol, n- and i-amyl alcohol,benzyl alcohol and 1-methoxy-2-propanol. Water may also be employed asdiluent.

If it is intended to prepare seed-dressing products, stickers may alsobe employed for formulating the powders according to the invention.Suitable materials are all customary binders which can be employed inseed-dressing products. Materials which may preferably be mentioned arepolyvinylpyrrolidone, polyvinyl acetate, polyvinyl alcohol and tylose.

Especially preferred as stickers are also dispersions of biodegradablepolyester/polyurethane/polyureas in water. Such dispersions are known(cf.

WO 01-17347).

The powder formulations according to the invention, either as such orelse after mixing with further formulation auxiliaries and/or planttreatment agents and, if appropriate, after further dilution with water,can be employed in practice. They are applied by customary methods, thatis to say for example by broadcasting, pouring, spraying or atomizing.

It is especially advantageous to convert the powders according to theinvention, by adding suitable formulation auxiliaries and, ifappropriate, diluents, into seed-dressing products with which a widerange of seed can be treated. Thus, such seed-dressing products aresuitable for dressing the seed of cereals such as wheat, barley, rye,oats and triticale, and of the seed of rice, maize, oilseed rape, peas,field beans, cotton, sunflowers and beet, or else the widest possiblerange of vegetable seed. The seed-dressing product formulations may alsobe employed for dressing the seed of transgenic plants. In this context,synergistic effects may be observed in combination with the substancesformed by expression. Suitable mixing apparatus for treating the seedwith the seed-dressing product formulations are all those which canconventionally be employed for the treatment of seed. Specifically,seed-dressing is done by introducing the seed into a mixer, adding thedesired amount of seed-dressing product formulations either as such orafter previously diluting them with water, and mixing until theformulation is distributed uniformly on the seed. If appropriate, thisis followed by a drying process.

The powder formulations according to the invention and the formulationswhich can be prepared therefrom by further mixing with formulationauxiliaries and/or plant treatment compositions are outstandinglysuitable for applying agrochemical active compounds to plants and/ortheir environment. They ensure that the active components are releasedover a prolonged period in the specific amount desired.

The rate of application of the powder formulations according to theinvention and of the preparations which can be prepared therefrom byfurther mixing with formulation auxiliaries can be varied within asubstantial range. It depends on the agrochemical active compounds whichare present in each case, their content in the plant treatmentcompositions, the indication in question, and the field of application.

The preparation and the use of the powder formulations according to theinvention is illustrated by the examples which follow.

PREPARATION EXAMPLES

A) Preparation of Hydroxyl-Containing Polyesters

Examples 1 to 4

Preparation of Terephthalic Polyester.

The starting materials terephthalic acid (TS), dimethyl terephthalate(DMT), 1,6-hexanediol (HD), neopentyl glycol-(NPG),1,4-dimethylolcyclohexane (CMC) and trimethylolpropane (TMP)—wereintroduced into a reactor and warmed with the aid of an oil bath. Aftermost of the materials have melted, 0.05% by weight of di-n-butyltinoxide was added at a temperature of 160° C. to act as catalyst. Thefirst elimination of methanol occurred at a temperature of approx. 170°C. The reaction was completed within 6 to 8 hours. The polyester wascooled to 200° C., and most of the volatile components were removedwithin 30 to 45 minutes by applying a vacuum (10 mbar). During theentire reaction time, the bottom product was stirred, and a gentlestream of nitrogen was passed through the reaction mixture.

The composition of the polyesters obtained together with their physicaland chemical characteristics are listed in Tables 1 and 2 which follow.TABLE 1 Composition of the polyesters of Examples 1 to 4 Startingmaterials Exam- TS DMT HD NPG DMD TMP ple mole(s) mole(s) mole(s)mole(s) mole(s) mole(s) 1 11 11 9.75 11 — 2.9 2 10 10 6.25 10.5 2 2.9 312 12 8 10.25 4.5 2.9 4 — 9 — 4 3.75 2.5

TABLE 2 Chemical and physical characteristics of the polyesters ofExamples 1 to 4 Ex- Acid Melting Viscosity at am- OH number number pointDTA 160° C. ple mg KOH/g mg KOH/g ° C. ° C. mPa · s 1 50-55 3-4 approx.75 approx. 50 ˜22000 2 55-60 2-4 approx. 75 approx. 50 ˜25000 3 44-483-4 approx. 75 approx. 50 ˜25000 4 100-105 <2 approx. 85 approx. 59˜20000

Example 5

In a stirred four-necked flask apparatus, 503 g (3.03 mol) ofterephthalic acid, 587.8 g (3.03 mol) of dimethyl terephthalate, 58 g(0.4 mol) of adipic acid, 686.4 g (6.6 m61) of neopentyl glycol and 32 g(0.24 mol) of trimethylolpropane were warmed slowly under nitrogen. 1 gof dibutyltin oxide was added to the melt with stirring at 160° C.Methanol and water were subsequently distilled off in the course of 7hours at 170 to 220° C. and of 14 hours at 220° C. to 230° C. Theresulting polyester had an acid number of 4.7. The melt was cooled to200° C. and freed from volatile components within 30 minutes at 11 mbar.The melt was thereupon cooled to 160° C., and the polyester was pouredonto a Teflon tray. The resulting clear yellow nonsticky resin had anacid number of 4.4 and a glass transition temperature of 55° C. (DTA).

B) Preparation of Powder Formulations According to the Invention

Example 6

In a stirred four-necked flask apparatus, 490 g of the polyester knownunder the name CRYLCOAT®) 240 (UCB Chemicals/Belgium) are heated up to150° C. and melted. 210 g of imidacloprid are introduced portionwiseinto the melt at 140° C. to 150° C. Stirring of the mixture issubsequently continued at 150° C. to 160° C. until a clear melt isobtained, which is poured onto a Teflon tray. The resin, which is pureand nonsticky at room temperature, is comminuted and ground finely in ajet mill without cooling. Standard electron microscopy reveals particlesof a size of approx. 0.2 to 20 μm. The pulverulent polymer-bound planttreatment composition consists of 30% by weight of imidacloprid and 70%by weight of polyester.

Example 7

In a stirred four-necked flask apparatus, 68.5 g of the polyester knownunder the name CRYLCOAT® 240 (UCB Chemicals/Belgium) and 1.5 g of theemulsifier known under the name Atlox® LP 6 (Uniquema) are heated to150° C. melted. 30 g of imidacloprid are introduced into the melt at140° C. to 150° C. Stirring of the mixture is subsequently continued at150° C. to 160° C. until a clear melt is obtained, which is poured ontoa Teflon tray. Within 20 hours, the resin, which is pure and nonstickyat room temperature, is reduced to a powder in a ball mill and screenedto a particle size of <125 μm.

Example 8

In a stirred four-necked flask apparatus, 68.5 g of the polyester knownunder the name CRYLCOAT® 240 (UCB Chemicals/Belgium) and 1.5 g of theemulsifier known under the name Agrimer® 22 (ISP) are heated to 150° C.and melted. 30 g of imidacloprid are introduced into the melt at 140° C.to 150° C. Stirring of the mixture is subsequently continued at 150° C.to 160° C. until a clear melt is obtained, which is poured onto a Teflontray. Within 20 hours, the resin, which is pure and nonsticky at roomtemperature, is reduced to a powder in a ball mill and screened to aparticle size of <125/km.

C) Use examples

Example 9

Release of Active Compound

3531.5 mg of the powder of Example 6 are stirred in 1 litre of Cipac 500ppm water (=Standard Water C) at 25° C. The imidacloprid amounts to28.9% by weight of the powder employed. Accordingly, the initial weightof imidacloprid is 1020.6 mg.

Imidacloprid has a solubility in water of approximately 700 mg/litre at25° C.

Samples are taken from the stirred mixture after the stirring timesindicated in Table 3 below and are filtered through a 0.2/m microfilter.The imidacloprid concentration is determined in each of the filtrates.The active compound concentration is determined by means of HPLC: TABLE3 Sampling after [h] Imidacloprid content in stirring the sample [mg/l]0.25 24.1 0.5 34.1 1 45.7 2 50.52 4 53.15 6 60.73 24 81.72 72 115.0 168141.30 336 179.50 504 193.7

The data reveal that the powder formulation according to the inventionreleases the active compound in a controlled manner over a prolongedperiod.

EXAMPLE 10

Rice seed dressing

3.34 g of the powder formulation of Example 6 are stirred with 12 g ofwater, 0.4 g of sticker (Impranil DLN D50, Bayer AG) and 1 g of a 1% byweight strength aqueous solution of the colorant LEVANYL RED BB-LF(Bayer AG) to give a seed-dressing fluid. This is applied to 200 g ofdehusked rice kernels cv. KOSHIHIKARA. The rice kernels treated in thisway are subsequently moved by hand in a dish until the individual ricekernels no longer adhere to each other. The dressed seed is then driedfor 16 hours at 40° C. All rice kernels are coated. No abrasion isobserved.

EXAMPLE 11

Rice Seed Dressing

1.67 g of the powder formulation of Example 6 and 2.5 g of acommercially available carpropamid formulation with a carpropamidcontent of 40% by weight are stirred with 4 g of water, 0.2 g of sticker(Impranil DLN W50, Bayer AG) and 1 g of a 1% by weight strength aqueoussolution of the colorant LEVANYL RED BB-LF (Bayer AG) to give aseed-dressing fluid. This is applied to 100 g of dehusked rice kernelscv. KOSHIHIKARA. The rice kernels treated in this way are subsequentlymoved by hand in a dish until the individual rice kernels no longeradhere to each other. The dressed seed is then dried for 16 hours at 40°C. All rice kernels are coated. No abrasion is observed.

Example 12

Rice Seed Dressing

In three different batches, in each case 18.5 g of rice kernels cv.Koshihikari dehusked are treated with in each case 200 μl of water in aseed-dressing apparatus. Thereafter, 55.5 μl of adhesive (Impranil DNL D50, Bayer AG) are added to each batch. Immediately thereafter, thebatches thus treated are mixed separately

-   -   a) with 123.3 mg,    -   b) with 246.7 mg or    -   c) with 616.7 mg        of powder formulation of Example 6, with rotation. In this        manner, dressed seed whose active ingredient concentration is    -   a) 200 g per 100 kg of seed,    -   b) 400 g per 100 kg of seed and    -   c) 1000 g per 100 kg of seed, respectively,        is obtained. All rice kernels are coated. No abrasion is        observed.

EXAMPLE 13

Tolerance Test

Dishes 17 cm×13 cm in size whose bottom is covered with 4 cm of sievedand steamed agricultural soil are planted uniformly in each case with

-   -   in each case 18.5 g of dressed rice kernels from each of the        three samples prepared as described in Example 12 or    -   in each case 18.5 g of rice kernels which have been treated in        the same manner with a commercially available, liquid        Imidacloprid seed-dressing formulation.    -   The rice kernels are subsequently covered with 1 cm of soil.

The dishes are then placed into a chamber in which the relative airmoisture is 90% and in which a daytime temperature of 24° C. and anighttime temperature of 15° C. prevails.

After the periods stated in Table 4 hereinbelow post-sowing, the plantsare examined for damage. Features which are determined are necroses,yellowing, abnormal growth and deformation. The total of all symptoms ofdamage is expressed in percent. 0% means that no damage is observed,while 100% means that the plants are completely damaged.

The preparations employed, the application rates of active compound andthe test results can be seen from the table which follows. TABLE 4Tolerance test Application rate Sample of of active ingredient Totaldamage in % after Example in g.a.i./100 kg seed 15 days 22 days 29 daysIn accordance a) 200 5 5 20 with the b) 400 5 5 15 invention c) 1000 1510 30 Example 12 known: 200 10 10 25 Imidacloprid seed- 400 15 10 40dressing formulation 1000 35 60 75 Control 0 2.5 10 20 (untreated)

1-8. (canceled)
 9. A powder formulation having a particle diameter ofunder 125 μm consisting of (a) one or more agrochemical activecompounds, (b) one or more biodegradable hydroxyl-containing polyesters,optionally in a mixture with one or more further biodegradable polymers,and (c) optionally, one or more additives.
 10. A powder formulationaccording to claim 9 wherein the polyester is one or morehydroxyl-containing terephthalate acid polyesters.
 11. A powderformulation according to claim 9 wherein the agrochemical activecompound is selected from the group consisting of imidacloprid,carpropamid, or mixtures thereof.
 12. A powder formulation according toclaim 9 consisting of (a) between 1 and 50% by weight of theagrochemical active compound, (b) between 50 and 99% by weight of thehydroxyl-containing polyester or a mixture thereof with one or moreadditional polymers, and (c) between 0 and 30% by weight of additives.13. A Process for the preparation of powder formulations according toclaim 9 comprising (1) homogenizing in the melt at temperatures ofbetween 50° C. and 180° C. a mixture of (a) one or more agrochemicalactive compounds, (b) one or more biodegradable hydroxyl-containingpolyesters, optionally in a mixture with one or more furtherbiodegradable polymers, and (c) optionally, one or more additives, and(2) comminuting the resultant mixture after cooling to obtain a powderhaving particles with a diameter under 125 μm.
 14. A method of applyingagrochemical active compounds comprising applying a powder formulationaccording to claim 9 to plants and/or their environment.
 15. A processfor the preparation of plant treatment compositions comprising mixing apowder formulation according to claim 9 with one or more extendersand/or surfactants.
 16. A plant treatment composition comprising aneffective amount of a powder formulation according to claim 9 inconjunction with one or more extenders and/or surfactants.